This invention relates generally to entryway systems and more specifically to techniques for sealing entryways against leaks, particularly during a blowing rainstorm.
Entryway systems used in building construction generally include a pair of vertically extending door jambs and a head jamb that frame the entryway and receive a hinged door. An elongated threshold assembly is attached at its ends to the bottoms of the door jambs and spans the threshold of the entryway. Many modern threshold assemblies include an extruded aluminum frame having an upwardly open channel from which a sill slopes outwardly and downwardly. A threshold cap, which may be made of plastic or wood, is disposed in the upwardly open channel and underlies a closed door mounted in the entryway. The threshold cap may be vertically adjustable to engage and form a seal with a flexible sweep attached to the bottom of the door. A flexible rubber or foam weather strip extends around the stop of the jamb and is captured and compressed between the stop and the outside face of the door when the door is closed to form a seal around the periphery of the door.
One common problem with traditional and modern entryway systems is the leaking of water into a building structure at the bottom corners of the closed door of the entryway. Entryways are especially susceptible to such leakage in a blowing rainstorm because, under such conditions, water tends to collect on the sill of the threshold assembly and puddles in the region adjacent the bottom corners of the door. This puddled rainwater, then, can be forced between the door, threshold, and jamb under the influence of air pressure created by the wind.
Manufacturers of entryway systems have attempted to address leakage at the bottom corners of a closed door in a number of ways, including placing a rectangular flexible or compressible corner pad on the bottom of the jamb where the jamb meets the threshold cap. The theory is that the corner pad will become captured and compressed between the door and jamb when the door is closed to fill the space between the door and the jamb at the bottom corner of the door, thus sealing against leakage of water at this location. A problem with these traditional rectangular corner pads is that leakage can still occur at the bottom corners of a closed door under conditions of blowing rainstorms. Under such conditions, rainwater tends to collect on the sill and puddle at the bottom corners of the entryway. In addition, the wind in a blowing rainstorm generates air pressure that is greater than the pressure within the dwelling on the other side of the door and that rises in proportion to the strength of the blowing wind. It has been discovered that, under such conditions, leakage can occur at the bottom corners of the door regardless of the integrity of the seal created between the weather strip and the door and between the door and the corner pad. Observation and experimentation has demonstrated that such leakage occurs as a result of weather strip wicking and not because of a poor seal between the weather strip and the door and the corner pad and the door. Specifically, when the door is shut against the weather strip, the weather strip folds to create its seal and this folding also forms a capillary channel, similar to a small straw, that extends upwardly along the length of the weather strip. High external air pressure generated by blowing wind and the pressure differences between the outside and inside of a building pushes rainwater up into the capillary channel in the weather strip. As the external air pressure increases relative to the internal air pressure within the building, water is forced higher into the capillary channel, eventually rising over the top of the corner pad and leaking into the building. It is now clear, therefore, that traditional rectangular corner pads have been a misguided and incomplete attempt to address the problem of leakage at the lower corners of a closed door.
Thus, there exist a need for an improved method and apparatus for addressing leakage at the bottom corners of a closed door particularly in conditions of blowing rain. It is to the provision of such a method and apparatus that the present invention is primarily directed.
Briefly described, the present invention, in one preferred embodiment thereof, comprises a unique entryway corner pad. The corner pad is sized to be mounted to bottom portion of a jamb of the entryway at the intersection of the jamb and the threshold cap. Thus, the corner pad resides in the space or gap between an edge of the door and the jamb when the door is shut and is located at a bottom corner of the door. The pad is made of a compressible material such as foam or rubber and has a thickness that is greater than the width of the gap between the edge of the closed door and the jamb. It will thus be seen that the corner pad becomes captured and compressed between the door edge and the jamb when the door is shut to form a seal therebetween, in much the same way as the conventional corner pads discussed above.
Unlike conventional corner pads, however, the corner pad of the present invention has an inside edge located adjacent the inside edge of the jamb and an outside edge located at or extending behind the bottom portion of the weather strip. A top edge of the corner pad joins the inside and outside edges and, in the preferred embodiment, is sloped downwardly and outwardly from the inside edge to the outside edge of the pad. When the door is shut, the corner pad becomes compressed between the door edge and the jamb to form a seal in the usual way. Uniquely, however, the downwardly and outwardly sloped top edge of the weather strip along with the jamb face and door edge forms a narrow triangular shaped reservoir in the region immediately above the corner pad.
In a blowing rainstorm wherein water is blown up the capillary formed by the weather strip as discussed above, the rising water within the weather strip eventually reaches the top of the outside edge of the corner pad. At this point, the water begins to spill over this outside edge. However, in contrast to prior art corner pads, the water does not flow over the corner pad and through the gap into a dwelling. Instead, it begins to collect in the triangular reservoir formed by the sloped top edge of the corner pad and faces of the jamb and door edge. The collecting water, in turn, disrupts the capillary action of the weather strip, preventing water from rising any higher within the capillary formed by the weather strip. At the same time, the rain water that collects in the triangular reservoir forms a head of pressure that increases as more water collects in the reservoir. This pressure increasingly opposes the force of wind pressure tending to drive more water up the weather strip. In practice, the reservoir is sized such that the pressure developed by collecting water within the reservoir is great enough to oppose even the most fierce blowing rain so that water never spills over the back of the triangular reservoir and into a dwelling. Thus, leaking at the bottom corner of the door is prevented. When the blowing rain subsides, the water collected in the triangular reservoir simply drains out onto the sill of the threshold assembly and away from the entryway.
Thus, an improved leak managing corner pad for entryways is now provided that addresses successfully the problems and shortcomings of the prior art. The corner pad successfully prevents water leakage at the bottom corners of a closed door in a blowing rainstorm by forming a seal in the traditional way. Uniquely, however, the corner pad also functions to disrupt the capillary flow of water up the weather strip and directs this water to a reservoir to form a head of pressure that opposes the force of windblown rain. When blowing rain subsides, the collected water drains safely away. These and other features, objects, and advantages of the invention will become more apparent upon review of the detailed description set forth below taken in conjunction with the accompanying drawing figures, which are briefly described as follows.